2003 Sea Islandia cavitating (240 Merc)

[dreaming1320]

Okay, I have spent the last few hours going through the forum looking for answers to my problem. I think that I have found the answers but I have a few questions prior to plowing into this repair.

Here is a quick run down on what the boat is doing. When I give the boat power (up to 7k rpm) it will not go more than 10 mph unless, I put everyone on the bow and then it will slowly plane. I have had the fortune of the ski rope being suck up into the jet (that was a fun afternoon with a filet knife). And I have sucked some rock into the jet recently. I recently had one of those days on the lake where the boat was not running right and it beached itself. When I went to pull off the beach it blew a lot of sand through the jet drive when I pulled off the beach.

So, I understand that I will need to change my wear ring. I found the string posted by Dr. Honda on how to change the wear ring. My first question is since my boat has the the larger (larger than a pwc) jet drive. Is the operation of changing out this wear ring basically the same on this jet drive as on the pwc?

Next question: Impeller Tool - I found one on ebay but not sure if there are different size impeller tools for the boats compared to the PWC. Are they universal?

While I am in there is there anything else I need to look at and possibly change out?

 

[Dr Honda]

You have a Merc. It's a totally different animal.

I don't have a ton of experience with them... but your pump has a replaceable mid body as it's wear ring... and you don't have to remove the impeller.

 

[ForHogan]

How do you know the wear ring needs replacing?

You can remove the reverse gate and stator without removing the impeller, and then you'll have a good look at the impeller as it sits in the wear ring. Only then will you really know what's going on.

One of my intake tines broke off and got sucked up and chewed up by the impeller making some real nicks in the impeller edges and a few in the wear ring too, and some nicks in the stator vanes. I sent the impeller off to Skat-Trak in california and they rebuilt it like new for about $250. I then used my dremel to smooth out a few rough spots in the wear ring and ground off the dents on the stator vanes. The rebuilt impeller fit perfectly with tight clearance and it runs like a champ now....right up on plane again.

The wear ring still has some nicks and scratches in it and the stator vanes are far from perfect....but the impeller was the real issue in my case. I think a new wear ring costs hundreds of dollars if I'm not mistaken and my manual says that in most cases, the impeller specs are more critical for performance.

The impeller removal tool (socket) and the impeller shaft tool (to lock the shaft for impeller removal) weren't cheap either. I bought them from this company:

http://www.marinepowerservice.com/

Mike